There is only one candidate, Republican or Democrat, who has been more opaque when it comes to allowing the American people to see their tax returns than Bernie Sanders: Donald Trump.

Bernie Sanders, who has made it his business to police other people's transparency practices, has released full tax returns tax returns for... zero years, though he released the summary for a single year, 2014. Compared to Sanders, John Kasich is more transparent (having released seven years of partial returns). Even Ted Cruz (who released four years of partial returns) has shown more commitment to transparency than Bernie.

For a while, Donald Trump held the record for the most ridiculous excuse ever not to release returns: that his returns are "under audit", which a publication no less conservative that Forbes points out is not an actual reason to hold back one's tax returns.

Move over, Donald. Bernie Sanders' wife and tax preparer Jane Sanders went on Bloomberg on Monday and came up with this excuse as to why Sen. and Mrs. Sanders have not yet released any of their full tax returns, which Mrs. Sanders said she filed using Intuit's tax preparation software Turbo Tax.

We have to go back and find them... We haven't been home for months!

She then proceeded to ask for time because she needs to go home and find the returns, conveniently putting the timeline after the New York primary.

Are. You. Kidding. Me. The campaign that is run almost entirely online is telling us that their tax returns aren't saved on a cloud service that is accessible from any device connected to the Internet?

Let me help you out there, Jane. Turbo Tax keeps full copies of your tax returns from previous years on record, on their servers. You log in, and viola! You have years of tax returns saved waiting for you to download and release to the media.

Also, there's another entity that is holding onto the copies of your tax return. The Internal Revenue Service. The tax transcripts for four years are free, and a copy of the full tax return only costs $57 - or roughly two average-sized donations to the Bernie Sanders campaign - and copies are generally available for six years.

In fact, we have even created a page for people who wish to give $57 in honor of Bernie's tax return dodge. This is our challenge to Bernie Sanders: Release your returns and show your books, and then if your campaign and personal cash isn't enough, we will even pay for this act of transparency for the American people if you won't.

Point is, there is no good excuse for a serious presidential candidate at this late stage to not have released their full tax returns for at least the better part of a decade. Sorry, but "I'm busy" is not an excuse. Then-Sen. Barack Obama, who'd only been a US Senator since 2005, released his tax returns in March of 2008 for years since 2000, and he did so before his opponent. Bernie Sanders has been in Congress for over 25 years, and in the Senate for more than nine.

Bernie Sanders has dismissed concerns about the secrecy around his tax returns by saying that there's "nothing exciting" in his returns.

But releasing tax returns is not about excitement. It's about trust. Trust, that is, that goes both ways. A candidate for president asks the American people to invest an enormous amount of trust, and in return, the people have a right to expect some trust from those seeking to lead us. Releasing the returns allows the American people to vet a presidential candidate to decide whether that candidate is worthy of our trust, and it allows the person aspiring to the highest office in the land to officially put their trust in the American people. By failing this test, Bernie Sanders is implying that to him, the trust of the people he wants to lead is at best irrelevant. Worse, by failing this test, he is plainly saying that he does not trust the American people.

Bernie Sanders has, time and again, demanded unprecedented transparency from his opponent, asking Hillary Clinton to release transcripts of a speech she gave when she was a private citizen. Yet he is asking to be excused from having to abide by the longtime standard of presidential candidates releasing their tax returns because his wife cannot find them yet.

No more excuses. No more passing the buck. No more stalling. Bernie Sanders must release at least the past seven years of returns without delay.